package com.yeren.utils;

import java.io.InputStream;
import java.io.Writer;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.core.util.QuickWriter;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
import com.thoughtworks.xstream.io.xml.PrettyPrintWriter;
import com.thoughtworks.xstream.io.xml.XppDriver;
import com.yeren.message.resp.Article;
import com.yeren.message.resp.ImageMessage;
import com.yeren.message.resp.MusicMessage;
import com.yeren.message.resp.NewsMessage;
import com.yeren.message.resp.TextMessage;
import com.yeren.message.resp.VideoMessage;
import com.yeren.message.resp.VoiceMessage;


/**
 * 消息处理工具类
 * @author liubiao
 *
 */
public class MessageUtil {
	//请求消息类型：文本
	public static final String REQ_MESSAGE_TYPE_TEXT="text";
	//请求消息类型：图片
	public static final String REQ_MESSAGE_TYPE_IMAGE="image";
	//请求消息类型：语音
	public static final String REQ_MESSAGE_TYPE_VOICE="voice";
	//请求消息类型：视频
	public static final String REQ_MESSAGE_TYPE_VIDEO="video";
	//请求消息类型：地理位置
	public static final String REQ_MESSAGE_TYPE_LOCATION="location";
	//请求消息类型：链接
	public static final String REQ_MESSAGE_TYPE_LINK="link";
	
	
	//请求消息类型：事件推送
	public static final String REQ_MESSAGE_TYPE_EVENT="event";
		
	
	//事件类型：subscribe（订阅）
	public static final String EVENT_TYPE_SUBSCRIBE="subscribe";
	//事件类型：unsubscribe（取消订阅）
	public static final String EVENT_TYPE_UNSUBSCRIBE="unsubscribe";
	//事件类型：scan（关注用户扫描带参数二维码）
	public static final String EVENT_TYPE_SCAN="scan";
	//事件类型：location（上报地理位置）
	public static final String EVENT_TYPE_LOCATION="LOCATION";
	//事件类型：click（自定义菜单）
	public static final String EVENT_TYPE_CLICK="CLICK";
	
	
	//响应消息类型：文本
	public static final String RESP_MESSAGE_TYPE_TEXT="text";
	//响应消息类型：图片
	public static final String RESP_MESSAGE_TYPE_IMAGE="image";
	//响应消息类型：语音
	public static final String RESP_MESSAGE_TYPE_VOICE="voice";
	//响应消息类型：视频
	public static final String RESP_MESSAGE_TYPE_VIDEO="video";
	//响应消息类型：音乐
	public static final String RESP_MESSAGE_TYPE_MUSIC="music";
	//响应消息类型：图文
	public static final String RESP_MESSAGE_TYPE_NEWS="news";
		
	/**
	 * 解析微信发来的请求（XML）	
	 * @param request
	 * @return
	 * @throws Exception
	 */
	@SuppressWarnings("unchecked")
	public static Map<String,String> parseXml(HttpServletRequest request)throws Exception{
		//将解析结果存储在HashMap中
		Map<String,String> map=new HashMap<String,String>();
		
		//从request中取得输入流
		InputStream inputStream=request.getInputStream();
		
		//读取输入流
		SAXReader reader =new SAXReader();
		Document document=reader.read(inputStream);
		
		//得到XML根元素
		Element root=document.getRootElement();
		
		//得到根元素所有的子节点
		List<Element> elementList=root.elements();
		
		//遍历所有子节点
		for(Element e:elementList){
			map.put(e.getName(), e.getText());
		}
		//释放资源
		inputStream.close();
		inputStream=null;
		return map;
		
	}
	
	/**
	 * 扩展xstream使其支持CDATA
	 */
	private static XStream xstream=new XStream(new XppDriver(){
		public HierarchicalStreamWriter createWriter(Writer out){
			return new PrettyPrintWriter(out){
				//对所有XML节点的转换都增加CDATA标记
				boolean cdata=true;
				
					@SuppressWarnings("unchecked")
					public void startNode(String name,Class clazz){
						super.startNode(name,clazz);
					}
				
					protected void writeText(QuickWriter writer,String text){
						if(cdata){
							writer.write("<![CDATA[");
							writer.write(text);
							writer.write("]]>");
						}else{
							writer.write(text);
						}
					}
			};
		}
	});
	
	
	/**
	 * 文本消息对象转换成XML
	 * @param textMessage 文本消息对象
	 * @return
	 */
	public static String messageToXml(TextMessage textMessage){
		xstream.alias("xml", textMessage.getClass());
		return xstream.toXML(textMessage);
	}
	
	/**
	 * 图片消息对象转换成XML
	 * @param imageMessage 图片消息对象
	 * @return
	 */
	public static String messageToXml(ImageMessage imageMessage){
		xstream.alias("xml", imageMessage.getClass());
		return xstream.toXML(imageMessage);
	}
	
	/**
	 * 语音消息对象转换成XML
	 * @param voiceMessage 语音消息对象
	 * @return
	 */
	public static String messageToXml(VoiceMessage voiceMessage){
		xstream.alias("xml", voiceMessage.getClass());
		return xstream.toXML(voiceMessage);
	}
	
	/**
	 * 视频消息对象转换成XML
	 * @param videoMessage 视频消息对象
	 * @return
	 */
	public static String messageToXml(VideoMessage videoMessage){
		xstream.alias("xml", videoMessage.getClass());
		return xstream.toXML(videoMessage);
	}
	
	/**
	 * 音乐消息对象转换成XML
	 * @param musicMessage 视音乐息对象
	 * @return
	 */
	public static String messageToXml(MusicMessage musicMessage){
		xstream.alias("xml", musicMessage.getClass());
		return xstream.toXML(musicMessage);
	}
	
	/**
	 * 图文消息对象转换成XML
	 * @param newsMessage 图文乐息对象
	 * @return
	 */
	public static String messageToXml(NewsMessage newsMessage){
		xstream.alias("xml", newsMessage.getClass());
		xstream.alias("item", new Article().getClass());
		return xstream.toXML(newsMessage);
	}
}
